def f_if(age):
    if age:
        print('age 不为零')
    print('finish')


def f_ifelif(age):
    if age >= 18:
        print('adult')
    elif age >= 6:
        print('teenager')
    else:
        print('kid')

    if age >= 18:
        print('adult')
    if age >= 6 and age <18:
        print('teenager')
    if age < 6:
        print('kid')
    

def f_ifelse(age):
    if age >= 18:
        print('adult')
    else:
        print('kid')


    if age >= 18:
        print('adult')
    if age < 18:
        print('kid')

#f_if('')
# f_if(0)
# f_ifelse(29)
# f_ifelse(13)
#f_ifelif(0)
f_ifelif(124)
#f_ifelif(7)